From f2db2e6cb3f5f766cbb3788af44705685ff2445a Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 23 May 2011 10:24:34 +0200 Subject: [S390] pfault: cpu hotplug vs missing completion interrupts On cpu hot remove a PFAULT CANCEL command is sent to the hypervisor which in turn will cancel all outstanding pfault requests that have been issued on that cpu (the same happens with a SIGP cpu reset). The result is that we end up with uninterruptible processes where the interrupt that would wake up these processes never arrives. In order to solve this all processes which wait for a pfault completion interrupt get woken up after a cpu hot remove. The worst case that could happen is that they fault again and in turn need to wait again. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/asm-offsets.c | 1 + arch/s390/kernel/entry.S | 1 + arch/s390/kernel/entry64.S | 1 + 3 files changed, 3 insertions(+) (limited to 'arch/s390/kernel') diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index ef455561101..edfbd17d708 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -124,6 +124,7 @@ int main(void) DEFINE(__LC_LAST_UPDATE_TIMER, offsetof(struct _lowcore, last_update_timer)); DEFINE(__LC_LAST_UPDATE_CLOCK, offsetof(struct _lowcore, last_update_clock)); DEFINE(__LC_CURRENT, offsetof(struct _lowcore, current_task)); + DEFINE(__LC_CURRENT_PID, offsetof(struct _lowcore, current_pid)); DEFINE(__LC_THREAD_INFO, offsetof(struct _lowcore, thread_info)); DEFINE(__LC_KERNEL_STACK, offsetof(struct _lowcore, kernel_stack)); DEFINE(__LC_ASYNC_STACK, offsetof(struct _lowcore, async_stack)); diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 1b67fc6ebdc..0476174dfff 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -212,6 +212,7 @@ __switch_to: lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4 lm %r6,%r15,__SF_GPRS(%r15) # load gprs of next task st %r3,__LC_CURRENT # store task struct of next + mvc __LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next st %r5,__LC_THREAD_INFO # store thread info of next ahi %r5,STACK_SIZE # end of kernel stack of next st %r5,__LC_KERNEL_STACK # store end of kernel stack diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index 9fd86456349..d61967e2eab 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -220,6 +220,7 @@ __switch_to: lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4 lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task stg %r3,__LC_CURRENT # store task struct of next + mvc __LC_CURRENT_PID+4(4,%r0),__TASK_pid(%r3) # store pid of next stg %r5,__LC_THREAD_INFO # store thread info of next aghi %r5,STACK_SIZE # end of kernel stack of next stg %r5,__LC_KERNEL_STACK # store end of kernel stack -- cgit v1.2.3-70-g09d2